Pole-changer.



0.1. ERICKSON.

POLE CHANGER.

APPLICATION HLED IAN. I8, 1910.

1,218,067". Patented Mar. 6, 1917.

2 SHEETS-SHEET I.

C. J. ERICKSON.

POLE CHANGER.

APPLICATION FILED JAN. 18. mu.

1 ,2 1 8,0 67 Patnbed Mar. (5, 1917.

2 SHEETS-SHEET 2 WXTNESSES jA/I/ENTOR;

UNITED STATES PATENT OFFICE.

CHARLES J. ERICKSOIV, OF CHICAGO, ILLINOIS, ASSIGNOR T AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

POLE-CHANGER.

Specification of Letters Patent.

Patented Mar. 6, 1917.

To all whom it may concern:

Be it known that 1, CHARLES J. ERICKSON,

a citizen of the United States of America,

and resident of Chicago Cook county, I1linois, have invented a certain new and useful Improvement in Pole-Changers, of which the "following is a specification.

My invention relates to pole changers of the kind that are used, for example, in selective signaling on party-lines in telephone systems. It relates to that particular kind of pole changer in which an electromagneti is provided with two armatures, one of which acts as a buzzer or interrupter for the t energizing circuit of the magne and the other of which controls the flow of current in the primary a transformer.

An object of my invention is to synchro nice the vibrations of the't wo armatures whereby the armature controls the flow of current in the primary of the tran former operates in exact synchronisrn with armature which controls the energizing circuit of the magnet, thus insuring a harmonic action for the entire mechanism of the pole changer whereby much more satisfactc-ry results are 0 tained than w possible with the old arrangement in 1c "b8 cit-vibration of the two arroatt s was some in which one armature dd not EU 2' :1 v Ute syncorcnousiy with tr e other arma- I -L A, contacts Curi eby the mecnoui n its operation o o a pole c en. 1 ples oi y inter ce shown in section to more 5 illustrate the construc 2 is "u end elevation of the some, 3 hows end of the pole changen is c of the circuits &c said pole ang r i iis thus ihustrated, the pole changer comprises a suitable support orbody-irarne A upon which is mounted aU-shaped support or frame The electromagnets C, C are Upon the top of said frame the mounting D is adjustably secured in place by the screws d and is provided with a downwardly-extending spring at. The pendulum E has its upper end secured to the said spring, and its lower end is provided with an adjustable weight 6. The said pendulum is provided with a circuit-controlling or interrupter spring 6 which is provided with a stifi backing spring e and which bears against the stationary Contact l which latter is mounted in a suitable binding post f. The pendulum E carries the armature G, which latter is arranged in operative relation to the cores or pole-pieces of the electromagnets. At the other end 0; the structure a bracket piece is secured to the top oi"- the frame Attached to the bracket H there is a down wardly projecting spring J to the lower end of which is secured swinging armature i in the same manner in h the penduis ing d. This :cli is held normally the contact 6 this contact being i suitable binding post T d" station iry con as SGT-Has m mi 1 c sure G,

in so don. i

e contacts c a Close toeoth r thus 1 For w a i giznig CiiCui'u. iois loo e or iess lam 2 a. terruption in the new or cool osin A I T 1 '4 I be 1*; through the eiectroniagnets is nus con-- trolled by the armature G whole. constituting is ordinariiy lino i as interrupter. This intermittent energizing of the electromagnets causes a corresponding energizing of the armature I. wili also be seen by referring to Figtthat this operating circuit isindependent of and totally distinct from the generating circuit N, which generating circuit includes the primary windings of a transformer or induction coil 0. The primary of the transformer 0 comprises two windings 0 and 0 One end of the winding 0 is connected to the binding post i and one end of the winding 0' is connected to the binding post Z. The remaining end of each winding is connected to the positive or grounded side of the battery M. The opposite end of the battery is connected to the movable contact 2' mounted upon the armature T. When the movable contact 2' engages the stationary contact 71 a circuit is closed through the primary winding 0 and when the contact i engages the contact L a circuit is closed through the winding 0. Thus, as the armature ll swings back and forth current will flow first through one of the secondary windings and then through the other. The two windings 0 and 0 are so connected that the currents flowing through them produce equal but opposite magnetic efiects in the core of the transformer. The alternating magnetism thus produced by the alternate energizing of the primary windings induces an alternating electromotive force in the secondary winding of. This alternating electromotive force has the same frequency as the vibration of the armatures G and T of the pole changer, and may be used to produce alternating current for operating electric bells or other signal-receiving devices which may be connected to the secondary winding of the transformer t).

In order to insure a steady and regular vibration for the armature I it is provided with an adjustable weight i similar to the weight 6 on the pendulum E. The weight 2' may be so adjusted that the natural period.

of vibration of the armature T is the same as that of the pendulum E, thus insuring a true harmonic vibration of said armature, and, consequently, the alternation of the current delivered by the transformer 0 is more regular than if the weight 2' were not provided.

With the arrangement shown and described it will be seen that the two armatures of the magnet operate in synchronismthat is to say, they not only have the samerate of vibration, but they also have the same amplitude and speed of vibration, the vibrations of one armature being an exact duplicate of those of the other armature. In this way better results are obtained, especially in connection with selective signaling systems, as, for example, those of party-lines in telephone systems, In such cases it is often necessary to adjust the pole changer to obtain a certain frequency of signaling current, and with my improved arrangement, whereby both armatures are adapted to be regulated for this purpose, the

will be seen that the current is not reversed in the primary of the transformer, as the primary is divided into two parts, its

middle point being permanently connected with the grounded pole of the battery. In this way current first flows through one part of the transformer, and then in the opposite direction'through the other part, thus reversing the magnetic polarity of the transformer. This method necessitates but a single movable contact for controlling the flow of current in the primary of the transformer, and thus the mechanism is not only simplified, but also materially improved in its operation.

What ll claim as my invention is:

1. Tn a pole changer, an electromagnet, two independently operating armatures for said magnet, an interrupter operated by one of said armatures, contacts operated by the other armature, a :pendulum carried by the armature which operates the interrupter, and a transformer comprising a primary circuit having a plurality of windings terminating in said other armature and its contact, means for controlling said other armature by means of a pendulum to maintain .the induced currents in the secondary in synchronism with said first armature, and a secondary responsive to the operations of said armature to produce an alternating signaling current.

2. In a pole changer, a circuit, a transformer secondary in said circuit, a battery,

an electromagnet, contacts operated by said magnet for interrupting the current-flow in the winding thereof, and means including two transformer primaries controlled alternately by said magnet for reversing the polarity or magnetic effect of the said transformer, whereby an alternating signaling current is induced in the said secondary, a pair of armatures for said magnet, one of said armatures controlled by a pendulum for the purpose of maintaining the induced currents in the secondary in synchronism with said other armature.

3. In a circuit controller, a magnet, an

armature for said magnet, an interrupter for said magnet, a battery, an energizing circuit for said magnet, said interrupter in said circuit, another armature for said magnet, a primary circuit, an interrupter Ior said primary circuit under the control of said other armature, a second circuit inductively related to said primary circuit, an adjustable pendulum for controlling said other armature to maintain the induced currents in the 10 second circuit in synchronism with said first armature.

Signed by me at Chicago, Cook county, Illinois, this 30 day of December, 1909.

\ CHARLES J. ERIOKSON. Witnesses: 4

EDWARD D. FALES, ARTHUR J RAY. 

